Specification

• RFC10023 on rfc-editor.org

FAQ & Quiz

• English FAQ
• Nederlandstalige FAQ
• Test your knowledge of the _for-sale DNS mechanism!

Demonstrators / Validators

• Original demo / validator (superseded)
• Userfriendly lookup demo (recommended)
• Another demo / syntax validator
• Tip: Experimental AI Agent 💡
• Minimal HTTP MCP server — Source

Third-party tools (with support) for RFC10023

• https://forsaledns.net/ - one of the earliest implementations and has a full website built around the concept
• https://for-sale-dns.hx-std.com/ - another, more basic lookup tool and record generator
• tldx - a tool that helps find available domain names fast
• happyDomain - centralizes the management of domain names
• IPWhois.net - a great lookup tool
• 'Inspect My DNS' has a banner on top when a _for-sale label is found
• IPAddress.to - great set of tools - the API output has nice info for debugging syntax errors
• rfc10023.de - Cool generator/validator - in German and English
• Dotweekly - Generator / checker - also incorporated in their other tools
• Domains Monitor is monitoring this as well (full dataset)
• EasyDNScheck - DNS checker
• DomaintoolBelt - for-sale market filter
• RDAP.ai - a domain research tool for exploring availability, and viewing RDAP registration data
• DomainKits MCP - has support in the API
• badge.forsale - feels a bit rough around the edges
• Experimental, but fully functional Chromium browser extension
• For-Sale MCP Server (Cloudflare Worker)

Marketplaces supporting RFC10023

• Atom (formerly Squadhelp) is a full-service domain registrar and premium marketplace.

Please note that there are quite a few more, such as NameShift, Namegarage and EliteDomains, but they support it silently, so we don't include links to them on this page.

Test Domains

Click a domain to copy it to your clipboard:

Additional Information

• Information page on GitHub
• Blog post on SIDN Labs website
• One pager website
• Flyer in PDF-format
• A real-world example of ForSale in action, on SIDN’s WHOIS page
• DIY option to put your .nl domain up for sale on SIDN
• An .nl specific article on the SIDN website about buying and selling domain names